The paper, forthcoming in the Tribal Law Journal, traces the origins of the requirement that persons have one-quarter or more Navajo blood to be enrolled in the Navajo Nation. Through minutes of the Navajo Nation Council and Bureau of Indian Affairs documents, the paper discusses the genesis of this requirement in the context of the development of the Nation's natural resources and the Nation's attempts to adopt a tribal constitution. The paper further examines recent unsuccessful efforts to revise the requirement, and the possibility of challenges to the requirement under the recently passed statute mandating application of the Fundamental Laws of the Dine.